Various types of anastomosis connectors, for connecting two blood vessels, have been suggested in the art.
One drawback of some connectors is their non-trivial profile, i.e., the connectors project outside of the volume defined by the anastomosis region. As many such connectors are formed of hard materials, these extensions may damage nearby tissue. One cause of these projections has been the use of spikes that are bent during the anastomosis procedure. A bent spike requires a non-trivial bending radius, to prevent spike failure, especially if the spike is elastic, super elastic or shape-memory based. It is noted that elastic, super-elastic and shape-memory bending mechanisms are limited with respect to the amount of elongation that the mechanism can faithfully retain. With plastic deformations, the bending is limited by the danger of mechanical failure. In general, the range of materials (and their mechanical characteristics) available for implantation is quite limited, due to bio-compatibility considerations.
U.S. Pat. No. 5,234,447 to Kaster, the disclosure of which is incorporated herein by reference, describes a plastically deformed anastomosis device for a side to end anastomosis between a side vessel and an everted graft. The device comprises a solid ring having a plurality of forward spikes and a plurality of backwards spikes extending axially from the ring. Forward spikes exit through the tip of the everted graft and typically engage the target side vessel from inside. Backward spikes do not need to pierce the graft and engage the target vessel from its outside.